This invention relates in general to wheelchairs and more particularly, to tie down points for wheelchairs. Most particularly, the invention relates to a tie down bracket for wheelchairs to create tie down points for securing a wheel chair in a vehicle.
Wheelchairs generally include a frame that supports a pair of drive wheels and a pair of front casters. The drive wheels and casters are typically rigidly supported by the wheelchair frame. The drive wheels make contact with the ground and are driven to propel the wheelchair. The drive wheels may be driven manually or powered by an electrical motor. The wheelchair supports a seat assembly comprising a seat and a backrest. The seat assembly is oriented above and between the drive wheels and the front casters to provide stability.
Wheel chairs are frequently transported in vehicles with the user in them. Typically, the user drives the wheelchair onto a lift attached to the vehicle. The lift is operated to raise the wheelchair into the vehicle. The user stays in the wheelchair while the vehicle is being driven. Often, the wheelchair is secured simply by setting the brakes. Perhaps some minimum kind of tie down is provided. At worst this tie down might consist of nothing more than opposing shock cords that do little more than prevent rocking of the wheelchair as the vehicle turns. At best, high-test nylon webbing is looped through any convenient location in the frame or wheels.
Tremendous forces are generated inside a vehicle every time an accident occurs. These forces are so great that it is not uncommon for individuals secured to a vehicle seat with a lap and shoulder harness to suffer injuries ranging from deep bruising to cracked ribs. Obviously, someone sitting in an unsecured or barely secured wheelchair will be severely injured. The likelihood of injury decreases if the wheelchair is secured with webbing. However, the combination of a motorized wheelchair and its user can easily weigh 500 lbs. (227 kg). In an accident, the force generated by such mass is focused at the point where the webbing passes through the frame or wheels. Considering that typical casual tie down points are not engineered to withstand such focused forces, its not surprising that wheelchairs fail to stay secured in place during vehicle accidents.
Thus is would be desirable to have tie down points through which a wheelchair could be safely and securely tied down in a vehicle.